Depression is a medical condition that can cause a wide variety of psychological and physical symptoms. It is estimated that between 4 and 8 percent of adolescents are depressed. However, depression in adolescents is probably underdiagnosed because the symptoms can be difficult to recognize.

Extreme and enduring sadness is the best-known symptom of depression, although adolescents can have a number of other symptoms, including irritability, difficulty at school, changes in sleep habits, and/or feelings of worthlessness. Depression is different than occasional blues and grief because depression is persistent and often interferes with the teen's ability to get along with parents and friends, complete school work, and appropriately participate in other normal daily activities.

Depression is a treatable condition. Psychotherapy (counseling), drug therapy, and other measures can alleviate symptoms and help the adolescent to succeed in school, develop and maintain healthy relationships, and feel more self-confident. This topic review discusses the causes, risk factors, signs and symptoms, and diagnosis of depression in adolescents. A separate topic review discusses the treatment of depression in adolescents. (See "Patient information: Depression treatment options for adolescents (Beyond the Basics)".)

Topics that discuss depression in adults are also available. (See "Patient information: Depression in adults (Beyond the Basics)" and "Patient information: Depression treatment options for adults (Beyond the Basics)".)

CAUSE OF DEPRESSION

The exact cause of depression is not known. Studies suggest that depression is a biologic disorder resulting, at least in part, from an imbalance of neurochemicals in the brain, including serotonin, norepinephrine, and dopamine. These neurochemicals allow cells in the brain to communicate with each other and play an...